I wouldn't believe it if I didn't see it with my own eyes

[Houdini]

I received my 8926 on 7/2, and after 24 hours it was only 3 seconds fast.
I just check it today (9 days later), after no adjustments or manual winding (just daily wear), and its only 1 second behind http://www.time.gov/

I didn't think this accuracy was possible. I imagine this must be fairly uncommon, no?

[shimside11]

After two years with my 8926, I was curious about the accuracy so I tested it over a couple of weeks. It was generally within COSC specifications. It averaged under 5 seconds fast per day, with some care to let it rest in various positions to compensate. I'm impressed with the Miyota 8215. For an inexpensive movement it performs very well.

In the interest of full disclosure, I do also have an 8927 TT Pro Diver that is about 15 to 20 seconds fast per day. I guess every one is different, but it appears that you could probably regulate most individual 8215 movements to get fairly close to COSC.

[timebender]

A non COSC movement should be accurate to a +-12 seconds per day according to two watch repairman I have talked with. They also said often they are better than that. So when your non-COSC is within the -4+6 area, you just have no complaints at all and the watch is doing superb!

I have one non-COSC that does as well as +2 a day and there is no way I would touch it as far as regulation. Another seems to be averaging at about +8 a day and as it is under the +12 I am leaving it alone also.

Congrats on a very accurate piece!

[two21b]

So, the question comes up again. Is it worth the extra money to pay for COSC certification?

[timebender]

So, the question comes up again. Is it worth the extra money to pay for COSC certification?

Your question is a valid one as even though a non certified movement is not guaranteed to be within that narrow measure, many of them still in fact are.

Still, I think there are two considerations here. One, many times you are buying more than just the certified movement anyway and two, if it is certified then the manufacturer must regulate it to those specs or give you a new watch/movement that can be regulated to such. Of course on the latter that would only be if your watch is warrantied. With at least one brand the warranty is for life to the original owner.

On a non cert, they get it within 12 secs either way and they are done with it. With me, when I feel accuracy is a must, I just default to one of my quartz. After all a good quartz will not gain/lose in a month what even a COSC will in a day.

[boscoe]

So, the question comes up again. Is it worth the extra money to pay for COSC certification?

I'd say yes - within certain boundries - since it is like the Good House Keeping Seal of Approval. Also, COSC movements produced by ETA are seriously upgraded from the normal/base model of the same line. In addition to being accurate, they are more durable.
There's a thread in the Reference Forum (as I recall) explaining the levels of ETA movements and why COSC is the top grade. It was written by James Elesner (sp - my apologies James), who owns several Swiss watch brands including EL, which is a WTF sponsor.

[BlueDevil]

So, the question comes up again. Is it worth the extra money to pay for COSC certification?

I think yes, especially at Invicta prices compared to the major COSC Swiss brands. (though it will remain on my wish list for now
I think we all love mechanical watches largely because you have functional art ticking away on your wrist, full quartz accuracy be ****ed...
...so the more refined/durable/attractive/accurate it can be the better!